The Cutaneous Glands of Comnion Toads. 325 



the body becomes inflated and is then stretched much beyond its 

 normal size. The grouping of glands on the dorsal surface quite 

 overshadows the wrinkles caused by the elastic fibers; but on the 

 ventral surface the wrinkles are of nearly equal importance with the 

 glands, in producing the unevenness. 



To the naked eye, the ventral skin has a rather uniformly flaked 

 or blocked off appearance. In one individual the blocks may be 

 conical in form, in another rounded eminences, while in others they 

 appear as flattened pavement. At the areas of transition into dorsal 

 skin, the flakes increase in size, and the uniformity is gradually 

 broken up by the occurrence of warts. Moreover, the skin at the 

 bend of the limbs does not have the blocked-off appearance. It 

 either lies in creases or is smoothly stretched. In the area of the 

 ventral skin at the union of the thighs, the blocks are larger and 

 quite unequal in size and shape. Sections from the lower side 

 show that the skin between the elevations is relatively very thin, 

 and the great variation is confined largely to the outer cutis layer. 

 The glands are sparsely scattered through the elevations (Fig. 15). 

 They are sometimes grouped but never have the close definite ar- 

 rangement that is found in the warts of the dorsal skin (Fig. 14), 

 nor do they ever attain the large size of those above. 



Classes of warts. The warts of the dorsal surface may be divided 

 into three classes: (1) The most prominent elevations which occur 

 on the dorsal surface are the so-called parotids (Fig. 9). They are 

 a pair of low, elongated, relatively smooth masses. These are located 

 on the back, each in line with and a short distance behind either eye, 

 the cranial crest alone intervening. The outer forward end of each 

 is in close proximity to the tympanum. The two parotids of a given 

 individual are quite alike in shape, color and dimensions. These 

 warts are constant for the species and are, as a rule, proportionate 

 to the size of the animal. The parotids of an average sized adult 

 measure about 6 by 13 mm. 



The remaining warts vary and can be described in general terms 

 only. 



(2) 'Next to the parotids the largest warts occur on the back 

 posterior to the parotids, on either side of the median line or groove. 



